1. Field of Technology
Embodiments disclosed herein relate to power supplies, and more specifically to managing transient load currents in a power supply.
2. Description of the Related Arts
Modern mobile devices such as laptops, smartphones and tablets typically include a re-chargeable battery to power the electronics inside. The batteries are often kept as small as possible in order to make the mobile device smaller and lighter. As a consequence, these batteries have finite capacity and a finite ability to deliver current to the load.
A battery's ability to deliver current is quantified by the internal resistance of the battery. When the battery is not connected to any loading circuit, it will show a particular voltage across its terminals called the “open circuit voltage.” When a loading circuit is connected to the battery, current flows from the battery through the loading circuit. This increase in current causes the voltage across the terminals of the battery to droop below its open circuit voltage. Batteries with a larger internal resistance will produce a larger voltage droop for a given load current.
These load currents may be particularly large in modern electronic devices that include multiple circuits operating from a single battery, such as for example, application processors, digital baseband processors, image processors, etc. During start up or under other transient conditions that produce large current drains from the battery, the battery's voltage may fall until the voltage is no longer sufficient to sustain the operation of the loading circuits, causing the entire device to reset.